Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
2000-05-16
2002-10-01
Klemanski, Helene (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C106S031580, C106S031640, C106S031860
Reexamination Certificate
active
06458193
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to washable coloring compositions comprising mixtures of specific low-molecular weight carboxylic acids and carboxylates. Such mixtures are produced through the partial neutralization of a carboxylic acid by a base to provide a relatively neutral pH mixture comprising some acid and some carboxylate species. Such mixtures provide excellent washability enhancing performance in association with colorants and inks. Also, these specific mixtures exhibit low viscosities which allow for greater amounts of washability enhancing additive and colorant to be added within colorant and ink formulations while simultaneously permitting the retention of sufficiently low overall viscosities of the target compositions. Such mixtures provide highly effective prevention of permanent colorations to certain substrates, such as skin, clothing, and the like, by the inks, dyes, and the like, within the target compositions. Marker styluses, writing implements, and other colorant transfer devices, containing these inventive compositions, are also encompassed within this invention.
DISCUSSION OF THE PRIOR ART
All U.S. and foreign patents cited within this specification are hereby incorporated by reference. The term “washable coloring composition” in conjunction with this invention is intended to encompass marker compositions (such as large childrens' markers and slimmer felt-tip pens, as merely examples), paints, spray-pattern indicators, and other colored compositions which can be removed from certain surfaces through contact with water and/or with detergents.
Washable coloring compositions, such as within ink markers, were developed in the past in order to provide children with writing and/or coloring implements which may not permanently stain or discolor certain surfaces, most notably clothing and skin. Such washable ink marker compositions generally require water-soluble colorants which also have a low affinity for coloring skin, clothing, and other surfaces, but which exhibit much higher affinity for coloring paper substrates. Although water-soluble polymeric colorants are preferred, acid dyes are also well known color components of such marker compositions.
The washability of such compositions is generally dependent upon the nature of the colorants or dyes utilized, but such a characteristic can be substantially improved by the presence of certain washability enhancing additives within the marker formulation. Such enhancers are a class of compounds (including polymers) which enhance washability and removal of the colorants from undesirable surfaces. Without intending to be bound by any scientific theory, it is believed that these enhancers function by either interacting with potential “stain sites” on the substrate before the colorant or ink, or interacting with the colorant at its reactive sites, thereby preventing the reaction of the substrate with the highly reactive sites of the colorant. In the past, such compounds have included dye-blocking polyaromatic sulfonates and their salts, such as described in U.S. Pat. No. 5,116,410 to Miller, European Patent Application No. 557,115 A1 to Kaiser et al., and PCT Application No. WO 98/36032 to Santini et al. Such specific dye-blockers have proven somewhat useful in preventing permanent colorations on certain substrates; however, many (such as sulfonated phenol/formaldehyde condensation products) are highly colored and as such tend to have an adverse effect on the brightness of some shades of the target marker composition, producing a shade with a dull, dirty appearance. This problem is particularly noticeable with regard to lighter color shades. As a result, it has proven difficult to produce certain colored markers without requiring extra amounts of colorant, etc., to compensate for the interference from the dye-blocker compounds. Furthermore, many of the prior art dye-blocker compounds possess very high viscosities which, when incorporated within standard ink markers, translate into higher overall viscosities for those target formulations. Such marker compositions generally must exhibit a viscosity of below about 7.0 centipoise in order to function properly and permit adequate flow of the colorant composition through the marker nib of the stylus. In order to adjust the viscosity, it has been necessary to reduce the amount of dye-blocker compound present in the target composition, which, in turn, translates into a less effective washable marker composition. The greater amount of dye-blocker compound, the greater the ability to prevent discolorations of certain substrates. Thus, there is a need to provide a washability enhancing agent within washable marker formulations which can be utilized in high proportions and which does not deleteriously increase the viscosity of the target composition.
Furthermore, the great amount of prior art dye-blocker compounds within target marker compositions has limited the use of such compositions to those stored within relatively large marker styluses (such as childrens' markers). A washability enhancing compound which can be utilized in relatively high proportions to permit increased washability while simultaneously not deleteriously increasing the intrinsic viscosity of the target composition would provide a heretofore unknown advantage within the washable coloring composition art.
DESCRIPTION OF THE INVENTION
It is thus an object of the invention to provide a washability enhancing compound of low molecular weight and low viscosity which is compatible with inks, colorants, dyes, and the like. It is another object of this invention to provide a washability enhancing compound which can be added in effective proportions to a marker composition without increasing the viscosity to a deleteriously high amount for standard marker performance. A further object of the invention is to provide a washable marker comprising a marker composition that is easily removed from surfaces such as skin and clothing but exhibits a high affinity for standard writing surfaces, such as paper. Yet another object of this invention is to provide a relatively inexpensive and yet highly effective washability enhancement additive for use within washable colorant compositions.
The present invention encompasses specific molecular weight compounds which conform to the following structure (I):
R—(CO
2
X)
n
(I)
wherein R is aliphatic (either linear, branched, cyclic, etc) and/or aromatic, n=1 to 4, and X is a counter-ion; and the aggregate number of carbon atoms within the structure is at most 22. The counter ion may be an alkali metal (such as sodium, potassium, and the like), hydrogen, ammonium, or an amine, wherein the pH of the composition is kept at a level from between about 5.5 and 9.0. The size of the aliphatic/aromatic radical, R, should be, at the most 21 carbons, preferably at most 18 carbons, preferably less than 12 carbons and most preferably 8 carbons or less. It has been found that the viscosity of the mixture becomes too great to provide effective washability enhancement once the aggregate carbon amount exceeds 22 in number, no matter what form the R group takes (i.e., whether an aromatic with multiple or long-chain moieties, or a highly branched aliphatic). Such a specific mixture of compounds, as a 20% aqueous solution, must also exhibit a viscosity of from about 1.0 to about 20 centipoise, preferably from about 1.5 to about 16, more preferably from about 1.5 to about 7, and most preferably from about 2 to about 6. Such mixtures, as aqueous solutions, although they may exhibit viscosities greater than the target 7.0 centipoise, are generally added to a coloring composition with a certain solids content. Upon introduction and mixing within the target compositions, the solutions are diluted and the overall viscosity of the resultant composition should be at most about 7.0 (if a marker composition is desired), although the final viscosity may be much higher if other types of washable coloring compositions are desired.
The pH level is of utmost importance to ensure
Klemanski Helene
Milliken & Company
Moyer Terry T.
Parks William S.
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